25 resultados para Xanthophylls.


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Egg yolk color may be controlled both by the concentration and the type of xanthophylls added to diets, with the aim of meeting consumers demand. The objectives of this work were to study how yellow and red xanthophylls present in laying hens` diets influence yolks colors and find the concentrations of these ingredients that meet the regional consumer desire. A factorial design 5 x 3 with 5 concentrations of yellow xanthophylls (lutein + zeaxantin 40%; 1.0, 1.25, 1.5, 1.75 and 2.0 mg/hen/d) and 3 concentrations of red xanthophylls (canthaxantin 10%; 0, 0.35, 0.7 mg/hen/d) was used. After a 30 d period receiving corn basal diets and water ad libitum, 60 White Dekalbe hens were distributed to receive the 15 dietary treatments in 4 replicates. Diets were provided daily at 110 g, during 21 d under 16 h light/8 h dark. Yolks colors were evaluated daily using the CIE L, a, b color space and the Roche color index. After the color stabilization, data were analyzed by ANOVA, regression analysis and Response Surface Methodology (MRS). Global acceptance for the Roche colors was evaluated with a 5 points hedonic scale and data were analyzed by Friedman and Dunn tests. Significance was established at 95% (P < 0.05). Regression analysis showed that the red xanthophylls content was the most important factor that defined L, a and b values for yolk color (P < 0.0001; square function), although its effect was significantly affected by the yellow xanthophylls contents (P = 0.0277; P < 0.0001; P = 0.0002 for L, a, b, respectively), providing evidence for a synergistic effect and not for a saturation effect. MRS showed that the highest redness of yolks was reached with 1.5 mg/hen/d of yellow and 0.5 mg/hen/d of red xanthophylls. So, higher supplementations aiming at increasing yolk color would bring an unnecessary cost to the ration. The most accepted yolk color scored 9, which corresponded to mean color attributes L = 65; a = 16; and b = 64. MRS showed that these values could be reached with combinations of yellow:red xanthophylls like 1.0:0.15 or 1.5:0.1 mg/ hen/d or simply with the yellow xanthophylls at 2.0 mg/hen/d. So, it was concluded that both yellow and red xanthophylls are important to define yolks color; that high amounts of xanthophylls are unnecessary to bring changes to color; and that Brazilian consumer requires yolks color attainable with few amounts of red xanthophylls or only with the yellow ones.

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Xanthophyll pigments have critical structural and functional roles in the photosynthetic light-harvesting complexes of algae and vascular plants. Genetic dissection of xanthophyll metabolism in the green alga Chlamydomonas reinhardtii revealed functions for specific xanthophylls in the nonradiative dissipation of excess absorbed light energy, measured as nonphotochemical quenching of chlorophyll fluorescence. Mutants with a defect in either the α- or β-branch of carotenoid biosynthesis exhibited less nonphotochemical quenching but were still able to tolerate high light. In contrast, a double mutant that was defective in the synthesis of lutein, loroxanthin (α-carotene branch), zeaxanthin, and antheraxanthin (β-carotene branch) had almost no nonphotochemical quenching and was extremely sensitive to high light. These results strongly suggest that in addition to the xanthophyll cycle pigments (zeaxanthin and antheraxanthin), α-carotene-derived xanthophylls such as lutein, which are structural components of the subunits of the light-harvesting complexes, contribute to the dissipation of excess absorbed light energy and the protection of plants from photo-oxidative damage.

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Barley (Hordeum vulgare L.) plants were grown at different photon flux densities ranging from 100 to 1800 μmol m−2 s−1 in air and/or in atmospheres with reduced levels of O2 and CO2. Low O2 and CO2 partial pressures allowed plants to grow under high photosystem II (PSII) excitation pressure, estimated in vivo by chlorophyll fluorescence measurements, at moderate photon flux densities. The xanthophyll-cycle pigments, the early light-inducible proteins, and their mRNA accumulated with increasing PSII excitation pressure irrespective of the way high excitation pressure was obtained (high-light irradiance or decreased CO2 and O2 availability). These findings indicate that the reduction state of electron transport chain components could be involved in light sensing for the regulation of nuclear-encoded chloroplast gene expression. In contrast, no correlation was found between the reduction state of PSII and various indicators of the PSII light-harvesting system, such as the chlorophyll a-to-b ratio, the abundance of the major pigment-protein complex of PSII (LHCII), the mRNA level of LHCII, the light-saturation curve of O2 evolution, and the induced chlorophyll-fluorescence rise. We conclude that the chlorophyll antenna size of PSII is not governed by the redox state of PSII in higher plants and, consequently, regulation of early light-inducible protein synthesis is different from that of LHCII.

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The present study measured a chemotherapy drug, etoposide, in pig cerebrospinal fluid after intraventricular administrations were made directly into the fourth ventricle of the brain; cytotoxic concentrations for a twenty-four hour period after infusions. The analytical method developed validates the potential treatment of malignant brain tumors. The increase in serum carotenoid concentration in 30 healthy individuals was measured after supplementation with lutein. HPLC analysis of serum levels of carotenoids showed an increase in the concentration of lutein and a constant concentration of other major serum carotenoids. An initial attempt to measure the enthalpy of aggregation of xanthophylls was conducted by using ultraviolet-visible spectroscopy. The enthalpy of lutein aggregation and AH range of zeaxanthin disordering of aggregation are reported. Monomethyl ether of lutein did not aggregate in any of the aqueous solutions.

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Vitamin E, vitamin A, and carotenoids are essential micronutrients for animals because of their antioxidant and immunostimulant functions and their implications for growth, development, and reproduction. In contrast to mammals and birds, information about their occurrence and distribution is generally lacking in reptiles, constraining our understanding of the use of these micronutrients. Using high-performance liquid chromatography, we determined the concentrations of vitamin E, vitamin A, and carotenoids in plasma, storage sites (liver and abdominal fat bodies), and in the colored ventral skin of male Common Lizards, Lacerta vivipara. All tissues shared a similar micronutrient profile, except the liver, which also showed traces of vitamin A(1). The main vitamin E compound present was a-tocopherol followed by lower concentrations of gamma-(beta-)tocopherol. Vitamin A(2) was the main vitamin A compound and it showed the highest concentration in the liver, where vitamin A(2) esters and traces of vitamin A(1) were found. Lutein was the main carotenoid, and it formed esters in the liver and the ventral skin. Zeaxanthin and low concentrations of beta-carotene were also present. The liver was the main storage site for carotenoid and vitamin A, whereas hepatic vitamin E concentrations resembled those present in abdominal Fat bodies. Compared with abdominal fat bodies, the ventral skin contained lower concentrations of vitamin A and vitamin E, but similar concentrations of carotenoicls. These results suggest that important differences exist in micronutrient presence, concentration, and distribution among tissues of lizards and other taxa such as birds and mammals.

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This work describes a simple and economical experiment for the extraction and purification of chlorophyll a from Spirulina maxima. Extraction and purification of natural compounds can be considered one of the most illustrative experiments that can be performed in Organic Chemistry courses. Particularly, the chromatography of dyes and pigments allows students to have a better comprehension of the chromatography separations. These compounds represent an important class of organic pigments applied in pharmaceutical, cosmetic, detergent compositions, and various other fields and can be extracted from plants and algae. To extract, separate and purify chlorophyll a from associated pigments such as xanthophylls, carotenes, and pheophytins, very costly processes are reported. The present approach is perfectly adequate for use in Chemistry experiments for undergraduate students.

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AbstractMaize is considered a source of carotenoids; however, these compounds are highly unstable, degraded by high temperatures, exposure to light and presence of oxygen. The objective of this work was to evaluate the influence of the moisture and type of drying applied to grains on the level of carotenoids in yellow maize. The experiment was conducted in a completely randomized design (2 × 4 factorial), two levels of initial moisture at the harvest (22 and 19%) and three types of drying (in the sun; in the shade and in a dryer) and control (no drying). The samples of grains after drying with 12% of final moisture were analyzed by concentration of total carotenoids, carotenes (α-carotene + β-carotene), monohydroxilated carotenoids (β-cryptoxanthin), and xanthophylls (lutein + zeaxanthin). Initial moisture, type of drying and the interaction between moisture versus drying influence (p≤0.05) the levels of carotenoids in grains. This is the first report about the drying conditions and harvest’s initial moisture as influence on the profile and content of carotenoids in maize grains. Based on the results, this work suggested that the harvest be carried out preferably when the grains present 22% humidity, with drying in a dryer or in shade for further use or storage.

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The group cyanobacteria includes a large number of organisms characterised by a low state of cellular organization. Their cells lack a well defined nucleus. Cell division is by division of the protoplast by an ingrowth of the septum. These organisms are characterised generally by a blue green colouration of the cell, the chief pigments being chlorophyll-a, carotenes, xanthophylls, C phycocyanin and C phycoerythrin. The product of photosynthesis is glycogen. These organisms lack flagellate reproductive bodies and there is a total lack of sexual reproduction. They are also unique because of the presence of murein in the place of cellulose (cell wall) and the absence of chloroplast, mitochondria and endoplasmic reticulum. Just like bacteria some of them possess Plasmids and can fix atmospheric nitrogen. In the present study growth kinetics, heavy metal tolerance, tolerance mechanisms, heavy metal intake, and antibacterial activity of §ynechocystics salina Wislouch - a nanoplanktonic, euryhaline, Cyanobacterium present in Cochin back waters has been carried out for the potential biotechnological application of this organism. _§; salina occur as small spherical cells of 3n diameter (sometimes in pairs) with bluish green colour. The species is characterised by jerky movement of the cells and is structrually similar to other cyanobacteria

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The present paper deals with the chemistry, isolation, separation, characterisation and stabilisation of the Marigold oleoresin and its application as a natural food colorant. Marigold (Tagetes Erecta L), an ornamental plant belonging to the composite family, has a rich source of natural antioxidant-Lutein. A natural pigment, xanthophylls offer an alternative to synthetic dyes as a food colorant, due to its non-toxicity. Chromatographic separations of saponified and unsaponified oleoresin were performed and Trans-Lutein identified as the major constituent. Well-preserved flowers exhibit a high yield of Xanthophyll content (105.19 g/Kg) in contrast to the unpreserved flower sample (54.87 g/Kg), emphasizing the significance of flower preservation in the extraction of xanthophyll. The stability and amount of xanthophyll also increased from 105.19 g/Kg to 226.88 g/Kg on saponification and subsequent purification with Ethylene Dichloride

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We evaluated the influence of dietry inclusion of corn gluten meal, apocartenoic acid ethyl ester (APO-EE), canthaxanthin, and Rhodocylus gelatinosus R-1 biomass on broiler carcass color. These oxycarotenoid sources were used as pigment supplements to a basal ration containing yellow corn as the sole source of xnathophylls. Objective color values of L (lightness),C (chroma), and h (hue) were measured on skin and meat surfaces of broiler carcasses. on both surfaces, R. gelatinosus R-1 biomass oxycarotenoids enhanced the chroma values (color saturation), as compared to yellow corn xanthophylls, and tended to provide yellowness to broiler carcasses, whereas the APO-EE and canthaxanthin tended to provide redness. At the concentrations studied, R. gelatinosus R-1 biomass oxycarotenoids were less effective than APO-EE and canthaxanthin in enhancing color saturation. Lightness, chroma, and blue values did not differ significantly between males and females. However, skin showed significantly higher color saturation than meat in breast and thigh portions of the carcass.

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To evaluate the relationship between carotenoid concentrations in serum and breast tissue, we measured serum carotenoid concentrations and endogenous carotenoid levels in breast adipose tissue of women with benign breast tumor (n = 46) or breast cancer (n = 44). Before extraction, serum was digested with lipase and cholesterol esterase, and breast adipose tissue was saponified. Serum and tissue carotenoids were extracted with ether/hexane and measured by using HPLC with a C30 column. Serum retinoic acid was extracted with chloroform/methanol and measured using HPLC with a C18 column. There were no significant differences in serum carotenoids [lutein, zeaxanthin, cryptoxanthin (both α- and β-), α-carotene, all-trans β-carotene, 13-cis β-carotene and lycopene], retinoids (retinol, all-trans and 13-cis retinoic acids), and α- and -γ- tocopherol concentrations between benign breast tumor patients and breast cancer patients. A substantial amount of 9-cis β- carotene was present in adipose tissue and was the only carotenoid that had a significantly lower level in benign breast tumor patients than in breast cancer patients. Correlations between carotenoid concentrations in serum and in breast adipose tissue were determined by combining the data of the two groups. Concentrations of the major serum carotenoids except cryptoxanthin showed significant correlations with breast adipose tissue carotenoid levels. When the concentrations of serum carotenoids were adjusted for serum triglycerides or LDL, correlations between serum carotenoid concentrations and breast adipose tissue carotenoid levels markedly increased, including that of cryptoxanthin (P <0.001). The strong correlation between serum carotenoid concentrations and endogenous breast adipose tissue carotenoid levels indicate that dietary intake influences adipose tissue carotenoid levels as well as serum concentrations, and that adipose tissue is a dynamic reservoir of fat-soluble nutrients.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)